Phosphorus: phosphorus pentachloride

phosphorus pentachloride is known by the following synonyms:

  • phosphorus pentachloride
  • phosphorus(V) chloride
  • phosphoric chloride
  • phosphorus chloride

The oxidation number of phosphorus in phosphorus pentachloride is 5.

  • Formula: PCl5
  • Hill system formula: Cl5P1
  • CAS registry number: [10026-13-8]
  • Formula weight: 208.237
  • Class: chloride
  • Colour: off-white
  • Appearance: crystalline solid
  • Melting point: 167°C
  • Boiling point: 160°C
  • Density: 2100 kg m-3


PCl3 + Cl2 → PCl5

Careful chlorination of phosphorus(III) trichloride results in phosphorus(V) pentachloride. The tyield is about 85%. Phosphorus(V) pentachloride is a white solid whose density is about 1600 kg m-3 and whose melting point is about 148°C under pressure. It sublimes at about 160°C.

Solid state structure

  • Geometry of phosphorus: mixed 4-, 6-coordinate: tetrahedral and octahedral
  • Prototypical structure:

Crystal structure of phosphorus pentachloride

Element analysis

Element percentages in phosphorus pentachloride
Element %
Cl 85.13
P 14.87

Isotope pattern for PCl5

THe chart below shows the calculated isotope pattern for the formula PCl5 with the most intense ion set to 100%.


Coming soon...


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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